/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.xkdx.guangguang.zxing;

import java.util.Collection;
import java.util.HashSet;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

import com.google.zxing.ResultPoint;
import com.xkdx.Zxing.camera.CameraManager;
import com.xkdx.caipiao.R;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 * 
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class ViewfinderView extends View {

	private static final int[] SCANNER_ALPHA = { 0, 64, 128, 192, 255, 192,
			128, 64 };
	private static final long ANIMATION_DELAY = 10L;
	private static final int OPAQUE = 0xFF;

	private final Paint paint;
	private Bitmap resultBitmap;
	private final int maskColor;
	private final int resultColor;
	private final int frameColor;
	private final int laserColor;
	private final int resultPointColor;
	private int scannerAlpha;
	private Collection<ResultPoint> possibleResultPoints;
	private Collection<ResultPoint> lastPossibleResultPoints;
	/**
	 * 四个绿色边角对应的长度
	 */
	private int ScreenRate;
	/**
	 * 手机的屏幕密度
	 */
	private static float density;

	/**
	 * 四个绿色边角对应的宽度
	 */
	private static final int CORNER_WIDTH = 5;

	/**
	 * 字体大小
	 */
	private static final int TEXT_SIZE = 16;
	/**
	 * 字体距离扫描框下面的距离
	 */
	private static final int TEXT_PADDING_TOP = 30;
	
	/**
	 * 中间滑动线的最顶端位置
	 */
	private int slideTop;

	/**
	 * 中间滑动线的最底端位置
	 */
	private int slideBottom;
	
	private boolean isFirst;
	
	/**
	 * 扫描框中的中间线的宽度
	 */
	private static final int MIDDLE_LINE_WIDTH = 6;

	/**
	 * 扫描框中的中间线的与扫描框左右的间隙
	 */
	private static final int MIDDLE_LINE_PADDING = 5;

	/**
	 * 中间那条线每次刷新移动的距离
	 */
	private static final int SPEEN_DISTANCE = 2;
	

	// This constructor is used when the class is built from an XML resource.
	public ViewfinderView(Context context, AttributeSet attrs) {
		super(context, attrs);

		// Initialize these once for performance rather than calling them every
		// time in onDraw().
		paint = new Paint();
		Resources resources = getResources();
		maskColor = resources.getColor(R.color.viewfinder_mask);
		resultColor = resources.getColor(R.color.result_view);
		frameColor = resources.getColor(R.color.help_button_view);
		laserColor = resources.getColor(R.color.viewfinder_laser);
		resultPointColor = resources.getColor(R.color.possible_result_points);
		scannerAlpha = 0;
		// 将像素转换成dp
		density = context.getResources().getDisplayMetrics().density;
		ScreenRate = (int) (25 * density);
		possibleResultPoints = new HashSet<ResultPoint>(5);
	}

	@Override
	public void onDraw(Canvas canvas) {
		Rect frame = CameraManager.get().getFramingRect();
		if (frame == null) {
			return;
		}
		
//		 初始化中间线滑动的最上边和最下边
		 if(!isFirst){
		 isFirst = true;
		 slideTop = frame.top;
		 slideBottom = frame.bottom;
		 }
		 
		int width = canvas.getWidth();
		int height = canvas.getHeight();

//		// 画扫描框下面的字
//		paint.setColor(Color.WHITE);
//		paint.setTextSize(TEXT_SIZE * density);
//		paint.setAlpha(0x40);
//		paint.setTypeface(Typeface.create("System", Typeface.BOLD));
//		canvas.drawText(getResources().getString(R.string.scan_text),
//				frame.left, (float) (frame.top - (float) TEXT_PADDING_TOP
//						* density), paint);

		// Draw the exterior (i.e. outside the framing rect) darkened
		paint.setColor(resultBitmap != null ? resultColor : maskColor);

		canvas.drawRect(0, 0, width, frame.top, paint);
		canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
		canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
				paint);
		canvas.drawRect(0, frame.bottom + 1, width, height, paint);

		if (resultBitmap != null) {
			// Draw the opaque result bitmap over the scanning rectangle
			paint.setAlpha(OPAQUE);
			canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
		} else {

			paint.setColor(Color.WHITE);
			canvas.drawRect(frame.left, frame.top, frame.right + 1,
					frame.top + 2, paint);
			canvas.drawRect(frame.left, frame.top + 2, frame.left + 2,
					frame.bottom - 1, paint);
			canvas.drawRect(frame.right - 1, frame.top, frame.right + 1,
					frame.bottom - 1, paint);
			canvas.drawRect(frame.left, frame.bottom - 1, frame.right + 1,
					frame.bottom + 1, paint);

			// 画扫描框边上的角，总共8个部分
			paint.setColor(Color.RED);
			canvas.drawRect(frame.left, frame.top - 1, frame.left + ScreenRate,
					frame.top + CORNER_WIDTH, paint);
			canvas.drawRect(frame.left - 1, frame.top, frame.left
					+ CORNER_WIDTH, frame.top + ScreenRate, paint);
			canvas.drawRect(frame.right - ScreenRate, frame.top - 1,
					frame.right, frame.top + CORNER_WIDTH, paint);
			canvas.drawRect(frame.right - CORNER_WIDTH, frame.top,
					frame.right + 1, frame.top + ScreenRate, paint);
			canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
					+ ScreenRate, frame.bottom + 1, paint);
			canvas.drawRect(frame.left, frame.bottom - ScreenRate, frame.left
					+ CORNER_WIDTH, frame.bottom + 1, paint);
			canvas.drawRect(frame.right - ScreenRate, frame.bottom
					- CORNER_WIDTH, frame.right + 1, frame.bottom + 1, paint);
			canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom
					- ScreenRate, frame.right + 1, frame.bottom + 1, paint);

			
			// 绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCE
			 slideTop += SPEEN_DISTANCE;
			 if(slideTop >= frame.bottom){
			 slideTop = frame.top;
			 }
			 canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop -
			 MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop +
			 MIDDLE_LINE_WIDTH/2, paint);
			 
			// Draw a red "laser scanner" line through the middle to show
			// decoding is active
			// paint.setColor(laserColor);
			// paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
			// scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
			// int middle = frame.height() / 2 + frame.top;
			// canvas.drawRect(frame.left + 2, middle - 1, frame.right - 1,
			// middle + 2, paint);

//			Collection<ResultPoint> currentPossible = possibleResultPoints;
//			Collection<ResultPoint> currentLast = lastPossibleResultPoints;
//			if (currentPossible.isEmpty()) {
//				lastPossibleResultPoints = null;
//			} else {
//				possibleResultPoints = new HashSet<ResultPoint>(5);
//				lastPossibleResultPoints = currentPossible;
//				paint.setAlpha(OPAQUE);
//				paint.setColor(resultPointColor);
//				for (ResultPoint point : currentPossible) {
//					canvas.drawCircle(frame.left + point.getX(), frame.top
//							+ point.getY(), 6.0f, paint);
//				}
//			}
//			if (currentLast != null) {
//				paint.setAlpha(OPAQUE / 2);
//				paint.setColor(resultPointColor);
//				for (ResultPoint point : currentLast) {
//					canvas.drawCircle(frame.left + point.getX(), frame.top
//							+ point.getY(), 3.0f, paint);
//				}
//			}

			// Request another update at the animation interval, but only
			// repaint the laser line,
			// not the entire viewfinder mask.
			postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
					frame.right, frame.bottom);
		}
	}

	public void drawViewfinder() {
		resultBitmap = null;
		invalidate();
	}

	/**
	 * Draw a bitmap with the result points highlighted instead of the live
	 * scanning display.
	 * 
	 * @param barcode
	 *            An image of the decoded barcode.
	 */
	public void drawResultBitmap(Bitmap barcode) {
		resultBitmap = barcode;
		invalidate();
	}

	public void addPossibleResultPoint(ResultPoint point) {
		possibleResultPoints.add(point);
	}

}
